Atomic View of Surface Self-Diffusion: Tungsten on Tungsten

Journal of Chemical Physics - Tập 44 Số 3 - Trang 1039-1049 - 1966
Gert Ehrlich1, F. G. Hudda1
1General Electric Research and Development Center Schenectady, New York

Tóm tắt

Surface diffusion of tungsten adatoms on several smooth, low-index planes of the tungsten lattice has for the first time been followed by direct observation of individual atoms in the field-ion microscope. Contrary to expectation, the mobility at room temperature is found to increase in the order (211) > (321) ∼ (110) > (310) ∼ (111). Migrating atoms are reflected at the boundaries of the (110), (211), and (321) planes; on the latter two, motion along atomic rows is favored over diffusion across lattice steps. From quantitative determinations of the rate of change of the mean-square displacement, diffusion coefficients are obtained as follows: (110), D=3×10−2exp(−22 000/RT)cm2/sec; (321), 1×10−3exp(−20 000/RT); (211), 2×10−7exp(−13 000/RT). Differences in diffusion on the (211) and (321), planes of very similar structure, suggest a weakening of interatomic forces at lattice edges.

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Tài liệu tham khảo

1963, Progr. Mater. Sci., 10, 395, 10.1016/0079-6425(63)90011-2

1949, Z. Physik, 126, 642, 10.1007/BF01328783

1961, J. Chem. Phys., 34, 1802, 10.1063/1.1701081

1965, Science, 149, 591, 10.1126/science.149.3684.591

1960, Advan. Electron. Electron Phys., 13, 83, 10.1016/S0065-2539(08)60210-3

1957, Z. Elektrochem., 61, 43

1963, Advan. Catalysis, 14, 255

1914, Sitzber. Akad. Wiss. Wien Math. Naturw. Kl., 123, 2381

1916, Kolloid-Z., 18, 48, 10.1007/BF01432660

1954, Z. Elektrochem., 58, 327

1941, Phys. Rev., 60, 661, 10.1103/PhysRev.60.661

1951, Phil. Trans. Roy. Soc. (London), 243, 299

1962, J. Chem. Phys., 37, 1606, 10.1063/1.1733348

1964, J. Appl. Phys., 35, 2271, 10.1063/1.1702840

Thông tin
Thông tin xuất bản

Journal of Chemical Physics

Tập 44 Số 3

1039-1049

Thông tin tác giả